// Copyright (c) Appeon. All rights reserved.
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. 
// You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0.

using System;

namespace SnapObjects.Data
{
    internal abstract class UpdateBuilderParser : SqlBuilderParser
    {
        public UpdateBuilderParser(
            ISqlStatementFactory factory,
            ISqlGenerationHelper helper,
            ITypeMapper typeMapper) : base(factory, helper, typeMapper)
        {
        }

        public override SqlStatement Parse(SqlBuildStatement statement)
        {
            var stmt = new SqlUpdateStatement();

            var update = (UpdateBuildStatement)statement;

            this.ParseBuildParameters(update);

            if (!this.ParseClause(
                update, stmt.Table, update.Table, SqlWhitespaceToken.Whitespace))
            {
                throw new InvalidCastException("Missing 'Update' table.");
            }

            if (!this.ParseClause(
                update, stmt.Set, update.Columns, new SqlCharacterToken(SqlCharacters.Comma)))
            {
                throw new InvalidCastException("Missing 'Update' column.");
            }

            this.ParseClause(
                update, stmt.From, update.From, SqlWhitespaceToken.Whitespace);

            this.ParseClause(
                update, stmt.From, update.Join, SqlWhitespaceToken.Whitespace);

            this.ParseClause(
                update, stmt.Where, update.Where, SqlWhitespaceToken.Whitespace);

            return stmt;
        }
    }
}
